#include <linux/slab.h>
#include <linux/compat.h>
#include <linux/err.h>
+#include <linux/bitmap.h>
#include <asm/ptrace.h>
#include <asm/syscall.h>
struct sel_arg_struct;
struct mmap_arg_struct;
+#ifdef IA32_NR_syscalls
+#define NR_compat_syscalls IA32_NR_syscalls
+#else
+#define NR_compat_syscalls NR_syscalls
+#endif
+
/*
* Take care of NOARGS not supported by mainline.
*/
#undef CREATE_SYSCALL_TABLE
+struct lttng_syscall_filter {
+ DECLARE_BITMAP(sc, NR_syscalls);
+ DECLARE_BITMAP(sc_compat, NR_compat_syscalls);
+};
+
static void syscall_entry_unknown(struct lttng_event *event,
struct pt_regs *regs, unsigned int id)
{
size_t table_len;
if (unlikely(is_compat_task())) {
+ struct lttng_syscall_filter *filter;
+
+ filter = rcu_dereference(chan->sc_filter);
+ if (filter) {
+ if (id >= NR_compat_syscalls
+ || !test_bit(id, filter->sc_compat)) {
+ /* System call filtered out. */
+ return;
+ }
+ }
table = compat_sc_table;
table_len = ARRAY_SIZE(compat_sc_table);
unknown_event = chan->sc_compat_unknown;
} else {
+ struct lttng_syscall_filter *filter;
+
+ filter = rcu_dereference(chan->sc_filter);
+ if (filter) {
+ if (id >= NR_syscalls
+ || !test_bit(id, filter->sc)) {
+ /* System call filtered out. */
+ return;
+ }
+ }
table = sc_table;
table_len = ARRAY_SIZE(sc_table);
unknown_event = chan->sc_unknown;
if (ret)
return ret;
#endif
- ret = lttng_wrapper_tracepoint_probe_register("sys_enter",
- (void *) syscall_entry_probe, chan);
- if (ret)
- return ret;
+ if (!chan->sys_enter_registered) {
+ ret = lttng_wrapper_tracepoint_probe_register("sys_enter",
+ (void *) syscall_entry_probe, chan);
+ if (ret)
+ return ret;
+ chan->sys_enter_registered = 1;
+ }
/*
* We change the name of sys_exit tracepoint due to namespace
* conflict with sys_exit syscall entry.
*/
- ret = lttng_wrapper_tracepoint_probe_register("sys_exit",
- (void *) __event_probe__exit_syscall,
- chan->sc_exit);
- if (ret) {
- WARN_ON_ONCE(lttng_wrapper_tracepoint_probe_unregister("sys_enter",
- (void *) syscall_entry_probe, chan));
+ if (!chan->sys_exit_registered) {
+ ret = lttng_wrapper_tracepoint_probe_register("sys_exit",
+ (void *) __event_probe__exit_syscall,
+ chan->sc_exit);
+ if (ret) {
+ WARN_ON_ONCE(lttng_wrapper_tracepoint_probe_unregister("sys_enter",
+ (void *) syscall_entry_probe, chan));
+ return ret;
+ }
+ chan->sys_exit_registered = 1;
}
return ret;
}
if (!chan->sc_table)
return 0;
- ret = lttng_wrapper_tracepoint_probe_unregister("sys_exit",
- (void *) __event_probe__exit_syscall,
- chan->sc_exit);
- if (ret)
- return ret;
- ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter",
- (void *) syscall_entry_probe, chan);
- if (ret)
- return ret;
+ if (chan->sys_enter_registered) {
+ ret = lttng_wrapper_tracepoint_probe_unregister("sys_exit",
+ (void *) __event_probe__exit_syscall,
+ chan->sc_exit);
+ if (ret)
+ return ret;
+ chan->sys_enter_registered = 0;
+ }
+ if (chan->sys_exit_registered) {
+ ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter",
+ (void *) syscall_entry_probe, chan);
+ if (ret)
+ return ret;
+ chan->sys_exit_registered = 0;
+ }
/* lttng_event destroy will be performed by lttng_session_destroy() */
kfree(chan->sc_table);
#ifdef CONFIG_COMPAT
kfree(chan->compat_sc_table);
#endif
+ kfree(chan->sc_filter);
+ return 0;
+}
+
+static
+int get_syscall_nr(const char *syscall_name)
+{
+ int syscall_nr = -1;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(sc_table); i++) {
+ const struct trace_syscall_entry *entry;
+
+ entry = &sc_table[i];
+ if (!entry->desc)
+ continue;
+ if (!strcmp(syscall_name, entry->desc->name)) {
+ syscall_nr = i;
+ break;
+ }
+ }
+ return syscall_nr;
+}
+
+static
+int get_compat_syscall_nr(const char *syscall_name)
+{
+ int syscall_nr = -1;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(compat_sc_table); i++) {
+ const struct trace_syscall_entry *entry;
+
+ entry = &compat_sc_table[i];
+ if (!entry->desc)
+ continue;
+ if (!strcmp(syscall_name, entry->desc->name)) {
+ syscall_nr = i;
+ break;
+ }
+ }
+ return syscall_nr;
+}
+
+int lttng_syscall_filter_enable(struct lttng_channel *chan,
+ const char *name)
+{
+ int syscall_nr, compat_syscall_nr, ret;
+ struct lttng_syscall_filter *filter;
+
+ WARN_ON_ONCE(!chan->sc_table);
+
+ if (!name) {
+ /* Enable all system calls by removing filter */
+ if (chan->sc_filter) {
+ filter = chan->sc_filter;
+ rcu_assign_pointer(chan->sc_filter, NULL);
+ synchronize_trace();
+ kfree(filter);
+ }
+ chan->syscall_all = 1;
+ return 0;
+ }
+
+ if (!chan->sc_filter) {
+ if (chan->syscall_all) {
+ /*
+ * All syscalls are already enabled.
+ */
+ return -EEXIST;
+ }
+ filter = kzalloc(sizeof(struct lttng_syscall_filter),
+ GFP_KERNEL);
+ if (!filter)
+ return -ENOMEM;
+ } else {
+ filter = chan->sc_filter;
+ }
+ syscall_nr = get_syscall_nr(name);
+ compat_syscall_nr = get_compat_syscall_nr(name);
+ if (syscall_nr < 0 && compat_syscall_nr < 0) {
+ ret = -ENOENT;
+ goto error;
+ }
+ if (syscall_nr >= 0) {
+ if (test_bit(syscall_nr, filter->sc)) {
+ ret = -EEXIST;
+ goto error;
+ }
+ bitmap_set(filter->sc, syscall_nr, 1);
+ }
+ if (compat_syscall_nr >= 0) {
+ if (test_bit(compat_syscall_nr, filter->sc_compat)) {
+ ret = -EEXIST;
+ goto error;
+ }
+ bitmap_set(filter->sc_compat, compat_syscall_nr, 1);
+ }
+ if (!chan->sc_filter)
+ rcu_assign_pointer(chan->sc_filter, filter);
+ return 0;
+
+error:
+ if (!chan->sc_filter)
+ kfree(filter);
+ return ret;
+}
+
+int lttng_syscall_filter_disable(struct lttng_channel *chan,
+ const char *name)
+{
+ int syscall_nr, compat_syscall_nr, ret;
+ struct lttng_syscall_filter *filter;
+
+ WARN_ON_ONCE(!chan->sc_table);
+
+ if (!chan->sc_filter) {
+ filter = kzalloc(sizeof(struct lttng_syscall_filter),
+ GFP_KERNEL);
+ if (!filter)
+ return -ENOMEM;
+ /* Trace all system calls, then apply disable. */
+ bitmap_set(filter->sc, 0, NR_syscalls);
+ bitmap_set(filter->sc_compat, 0, NR_compat_syscalls);
+ } else {
+ filter = chan->sc_filter;
+ }
+
+ syscall_nr = get_syscall_nr(name);
+ compat_syscall_nr = get_compat_syscall_nr(name);
+ if (syscall_nr < 0 && compat_syscall_nr < 0) {
+ ret = -ENOENT;
+ goto error;
+ }
+ if (syscall_nr >= 0) {
+ if (!test_bit(syscall_nr, chan->sc_filter->sc)) {
+ ret = -EEXIST;
+ goto error;
+ }
+ bitmap_clear(chan->sc_filter->sc, syscall_nr, 1);
+ }
+ if (compat_syscall_nr >= 0) {
+ if (!test_bit(compat_syscall_nr, chan->sc_filter->sc_compat)) {
+ ret = -EEXIST;
+ goto error;
+ }
+ bitmap_clear(chan->sc_filter->sc_compat, compat_syscall_nr, 1);
+ }
+ if (!chan->sc_filter)
+ rcu_assign_pointer(chan->sc_filter, filter);
+ chan->syscall_all = 0;
return 0;
+
+error:
+ if (!chan->sc_filter)
+ kfree(filter);
+ return ret;
}
projects / lttng-modules.git / blobdiff